Radio-frequency tuning assembly



Oct. 17, 1950 J. L. BONANNO mm FREQUENCY 'ruumc ASSEMBLY Filed Aug. 30, 1947 P114 Bamuw J32 71(- 5/! INVENTOR If 4 lbs! ATTORNEY turn Patented Oct. 17, 1950 2,526,454 RADIO-FREQUENCY TUNING ASSEMBLY Joseph L. Bonanno, Madison, N. 3., assignor to The Lionel Corporation, New York, N. Y., a corporation oi. New York Application August 30, 1947, Serial No. '1 71,448

4 Claims.

The present invention relates to radio frequency tuning assemblies and is more particularly directed toward tuning assemblies suitable for employment with wired frequency systems for the purpose of providing uni-directional current for control purposes.

The present device forms the receiver of an electronic control system suitable for supplying current to anelectromagnetic relay for controlling a toy railroad accessory such as a locomotive control and reversing switch, a whistle, a

pair 01' couplers, an unloading device, etc., or a thermal relay.

In such electronic toy railroad control systems radio frequency currents of a selected frequency are superimposed on the track circuit and such radio frequency currents are available at a location in the track circuit tuned to receive the same. For example ten such frequencies may be employed.

According to the present invention the receiver is permanently connected to the power and relines of the toy railroad layout and each receiver has a fixed condenser in series with the primary coil of a transformer having a movable magnetic core. By using a condenser of selected capacity with coil of selected primary turns and adjusting the core, it is possible to tune the frequency of the receiving circuit to correspond with a frequency sent out by the transmitter and so that it will not respond to the power supply frequency Or any one of the other frequencies of the system. When the transmitter supplies current of this one selected frequency to the circuit there is substantial current flow through the tuned receiving circuit and this supplies energy to the secondary coil of the transformer. Negligible currents flow through the other inductive elements in the track circuit. This secondary coil has outside leads connected through a full wave rectifier arrangement with the power supply and has a central output tap adapted to be connected to an electromagnetic relay coil, a thermal relay heater, or the like. The relay contact is connected to the load and to the power line leading to the transformer primary so that when the relay is closed, power may be sent to the load.

The present invention contemplates an improved assembly of these parts wherein the coils, the core and the rectiilers and all connections are in a small preassembled unit in which the metal parts are outside the field of the coil so as to minimize losses, and connections are made very short so as to further improve the operational characteristics of the receiver.

According to the present invention a single molded body serves to support all the wiring and metal parts.

The accompanying drawings show, for purposes of illustrating the present invention, an embodiment in which the invention may take form, it being understood that the drawings are illustrative of the invention rather than limiting the same.

In these drawings:

Figure l is an exploded perspective view illustrating the component parts making up the assembly;

Figure 2 is a top plan view of the assembly with parts broken away showing interior constructions;

Figure 3, 4 and 5 are sectional views on the line 33, 4-4 and 5-5 of Figure 2; and

Figure 6 is a wiring diagram.

Figure 6 shows input leads l0 and II which may, for example, be the contact roller and the wheels or grounded side of the toy vehicle. The

lead H is connected through a fixed condenser- I! of predetermined capacity (0.0005 mfd. for example) and the other side of the condenser is connected to a coil l3 connected with the other side In of the power-supply. This coil is inductively coupled with a step down secondary coil I4. This coil has a center tap l5 connected to the coil l8 of a relay R. The other side of the relay is connected to the power line In as is and I8 of the secondrectiflers l9 and 20, I0 and relay frame The insulated relay 22 obvious. The end leads l1 ary are connected through to the power supply lead which carries contact 2|. contact opposite II is brought to terminal which is connected to the load.

The body member of the assembly is illustrated at 30. It is preferably made of molded polystyrene or nylon and has a tubular cylindrical element 3| and bracket-line element 32. The tubular element has a deep recess 33 and a closed end slotted at 34 and threaded at 35 to receive a threaded member 36. This member 36 carries a magnetic core 31, the position of which can be adjusted in the recess by threading the member 36 back and forth. A split ring 3| fits tightly about the slotted end of the tube so as to grip the screw. This structure forms the sub- Ject matter of my application Serial No. 719,811, filed January 2, 1947.

The primary and secondary coils of the transformer are in a coil assembly indicated at 33 which is received on the tubular portion 3i of the body 30 immediately above the bracket portion 32. The bracket portion 32 of the body has two downwardly opening shallow recesses 40 and 4| with holes 42 and 43 extending up through the bracket portion. The bracket portion also has a central hole 44. Metal oxide rectiilers, pref erably copper oxide rectifiers, are indicated at 45 and 46. These rectifiers together with rectifier contactors 41 and 48 .are received in the reve el .0 and 4|, the contactors 41 and 48 having soldering lugs 50 extending up through theholes l2 and 43. The rectifiers and rectifier contactors are held in place by a rectifier cover 5| having prongs 52 folded over on top of the bracket as indicated in Figure 2. This cover plate BI is in contact with the copper side of each rectifier and has a soldering lug 53 which extends up through the hole 44. The lugs 50 are connected to the ends of the secondary, the lug 53 to the power supply and primary as indicated in the wiring diagram. .The assembly may be secured to an insulated support and connected to the relayR by a bolt passed through the holes 55 and 58. The relay and structure in which the relay and tuning assembly are employed forms the subject matter of my application for patent Serial No. 771,447, filed August 30, 1947.

Since it is obvious that the invention may be embodied in other forms and constructions within the scope of the claims, I wish it to be understood that the particular form shown is but one of these forms, and various modifications and changes being possible, I do not otherwise limit myself in any way with respect thereto.

What is claimed is:

1. A radio frequency tuning assembly comprising a unitary tubular core receiver and coil support and laterally extending bracket, a movable magnetic core in the receiver, a transformer coil assembly with primary and secondary coils about the support adjacent the bracket, the secondary having a central tap and twooutput leads, the bracket having two recesses opening away from the coilseach communicating with a hole through the bracket, rectifier contactor springs in the recesses and holes and connected to the output leads, rectifiers in the recesses, and a rectifier cover secured to the bracket and in contact with both rectifiers, the cover having a terminal extending through the bracket and connected to one of the primary leads.

2. A rectifier tuning assembly comprising an insulating body having a relatively long tubular portion with downwardly opening core recess and a laterally extending relatively thin portion having two downwardly opening rectifier recesses and three holes, two of which communicate with the rectifier recesses, a magnetic core adjustably carried in the core recess, a transformer having coils about the tubular portion and adjacent the hteraliy extending portion, rectifier contactors and a rectifier in each recess each contactor having a terminal extending through the corresponding hole and connected to a secondary lead from the transformer, a rectifier cover secured to the laterally extending portion' and having a terminal extending through the other hole and connected to the transformer primary, and an output tap at the center of the secondary coil of the transformer.

3. A device for producing uni-directional current from a radio frequency current when capacitatively coupled to a source of radio frequency current, comprising an insulating body carrying a movable magnetic core in a recess therein and transformer primary and secondary coils about the coil, and having a bracket extending lateralb of the coils, a pair of rectifiers secured to the bracket, contact elements connecting the rectifiers to the ends of the secondary coil, and a rectifier cover securing the rectifiers to the bracket andconnecting them to the primary, the secondary having a central output tap.

4. A radio frequency tuning assembly for use with a capacitatively coupled source of radio frequency current, comprising a transformer having a primary coil, a secondary coil having a centrally tapped output terminal, and a tuning core, a full wave rectifier connected to the source and the ends of the secondary, and a. common support for the aforesaid parts, said support having a core receiving recess, a concentric coil mounting, two rectifier receiving recesses, and a clamp member holding the reotifiers in place.

JOSEPH L. BONANNO.

REFERENCES CITED UNITED STATES PATENTS Name Date Dome Mar. 17, 1942 Hamann July 11, 1944 Schade May 1, 1945 Lyman Mar. 26, 1946 llumber 

